Apparatus for aerating granular material



Feb. 19, 1957 w. HORTH APPARATUS'FOR AERATING GRANULAR MATERIAL Filed April 1, 1952 2 Shets-Sheet 1 Feb. 19, 1957 w. HORTH 2,781,563

APPARATUS FOR AERATING GRANULAR MATERIAL Filed April 1, 1952 2 Sheets-Sheet 2 Waifer Hbrfh' United States Patent APPARATUS FOR AERATING GRANULAR MATERIAL Walter Horth, Chicago, Ill., assiguor to Herbert Simpson Corporation, Chicago, 11]., a corporation of Illinois Application April 1, 1952, Serial No. 279,848

2 Claims. (Cl. 22-89) to facilitate its use in further processing operations such I as in the making of foundry molds or ceramic bodies, and in many other applications where the end product is to be formed into a definite shape. For this purpose, material discharged from the mixer is passed through a device which in the foundry industry is called an aerator,

or a revivifier. Such an aerator commonly consists of a housing incorporating a feed opening and a discharge opening, with a rapidly rotating assembly within the housing equipped with combing bars for breaking up and flufiing the caked material to granular form without disturbing the composition of ingredients which the mixing process has created.

There has now been discovered an aerator of the above character which has radically increased speed capabilities, greatly increased service life, and yet makes possible a thirty to fifty percent reduction in power consumption.

It is, therefore, an object of the present invention to provide an apparatus for aerating granular material having a greatly reduced processing time for a given amount of material.

It is a further important object of the present invention to provide an apparatus for aerating granular material having a greatlyimproved service life.

It is another important object of" the present invention to provide an apparatus for aerating granular material having a greatly reduced power consumption.

It is a still further object of the present invention to provide aerator combing bars which are self-cleaning and whose action greatly reduces material build-up within the housing of the aerator.

It is still another object of the present invention to provide combing bars which are readily removable and which are readily adjustable to variations in pattern.

It is yet another object of the present invention to provide an apparatus for aerating granular material which is adjustable to accommodate different types of material.

It is a feature of the present invention to provide a combing bar assembly including a polygonal shaft, and a plurality of combing bars having polygonal sockets for receiving said shaft in a plurality of relative angular positions.

It is a further important feature of the present invention to provide a bar which imparts to the material to be aerated a glancing blow propelling the material sideways from the direction of rotation.

It is a still further feature of the present invention to assembly 15.

provide a plurality of such bars whereby a cross fire of particles at controlled velocities is established for breaking up caked material without destroying the coating on the granular particles.

Other and further important objects, features and advantages of the present invention will be apparent from the disclosures in the specification and the accompanying drawings, in which:

Figure 1 is a side elevational view of an apparatus for aerating granular material mounted for use in conjunction with a material mixer, a portion of the mixer casing being shown in dot-dash outline;

Figure 2 is a transverse sectional view of the apparatus of Figure 1;

Figure 3 is an enlarged elevational View of one of the combing bars of the aerator of Figure 1;

Figure 4 is a cross-sectional view taken substantially along the line IV -IV of Figure 3;

Figure 5 is an elevational view of a modified form of combing bar according to the present invention;

Figure 6 is a transverse sectional view of aerating apparatus utilizing the combing bar of Figure 5; and

Figure 7 is a partial cross-sectional view taken substantially along the line VII--VII of Figure 6.

The aerator of the present invention is illustrated as it would be mounted beneath the casing 10 of a sand mulling machine or the like, but it will be understood that the aerating apparatus may be used independently thereof for breaking up lumps of material, aerating the same and putting the same in a state of fineness in order that it may be readily used for molding or other purposes. The aerator housing 11 includes an inlet end 12 and an outlet end 13. In the embodiment illustrated, therefore, sand which has been mulled in the mixing chamber, is discharged into the aerator housing 11 at its inlet end 12 and is aerated by means of the aerating assembly 15 rotatably mounted within the housing 11 by means of the shaft 17. The shaft 17 is mounted for rotation in the bearings 18 and 19 on either side of the housing and may be driven by any suitable means.

Referring to Figure 1, it will be noted that the housing 11 is provided with a swingable door or gate 22 controlled by a lever arm 23. When the gate 22 is in the position shown in Figure l, the sand discharged from the mulling machine will be acted upon by the aerating However, when the gate 22 is swung upwardly, the sand will escape through an opening in the housing 11 without coming into contact with the aerating assembly.

Means are provided in connection with the aerating assembly for breaking up and pulverizing any lumps of sand that may be discharged from the mulling machine, or that may be fed into the aerator housing. In the illustrated form of this invention, the means above mentioned consists of a series of hammers or the like 25 which are freely j-ourrnalled upon a rod 26 mounted in the upper portion of the housing 11. The hammers cooperate with the sand aerating assembly 15 forbreaking up-thelumps of sand. An adjusting screw 27 and ha ndwheel 28 are provided for raising or lowering the hammers in order to vary the distance that they are supported from the aerating assembly 15. The hammers 25 are free to rise and fall in accordance with the lumps of sand passing between the same and the aerating assembly. A front door 30 is provided to afford convenient access to the interior of the housing.

As thus seen in Figure 2, the aerator assembly 15 comprises a plurality of combing bars 33 mounted along the shaft 17. The shaft is preferably of a hexagonal crosssection to receive the hexagonal openings or sockets 35 of the combing bars 33, Figure 3. As seen in Figure l, the bars may be mounted at different angles on the shaft 17, by virtue of the hexagonal openings 35. It will be understood that a number of patterns are possible; for example, the bars may be progressively arranged at 120 increments as shown in Figure 1, or the hairs may progress at 6 increments, or at 180 increments, and may be arranged in left or right hand spirals or in a spiral converging toward the center or toward the ends of the assembly. As a result, the potential range of application of the aerator assembly is greatly increased, since the combing bars may be arranged on the rotating shaft in accordance with the toughness of the material to be handled. In assembling the combing bars on the shaft, they are simply strung onto the shaft which locates the bars permanently in the radial direction. The two end bars may be equipped with set screws which fix the location of the combing bacr assembly in the axial direction.

As seen in Figures 3 and 4, the bar is of a generally crescent shape and is provided with a tapered or wedge shaped leading edge as indicated at 37. The leading edge is preferably provided with a hardening material 38, as indicated in Figure 4.

In Figure 5 is illustrated a bar 39 having a different type socket 40, wherein the bar is broken away across a portion of two sides of the hexagonal socket as indicated at 41 resulting in a considerable saving in material. Further as illustrated in Figures 5 and 6, the open socket 40 makes possible the assembly of the bars 39 on shaft 43 without removing the shaft from bearings 18', 19. This is accomplished by turning down a portion of the shaft indicated at 45 so that the diameter of the portion 45 is less than the gap 41 in socket 40. Thus a bar can be assembled on the shaft simply by slipping the open portion of the socket 40 over the reduced diameter shaft portion 45 and then orienting the bar so that the hexagonal socket 40 registers with the hexagonal portion 47 of shaft 43, as shown in Figure 7. The bar is then moved laterally along the shaft to its desired position. To replace worn combing bars, the two set screws 49, 50 are released, and the individual bars are moved laterally along the shaft and disengaged from the shaft at the turned down portion 45. It will be apparent that the entire circular portion of shaft 43 may have the diameter of the turned down portion 45 if desired.

The remainder of the aerator of Figure 6 is similar to the aerator of Figures 1 and 2, and corresponding parts have been given corresponding primed reference numerals.

The manner of operation of the aerator will now be understood. The shaft 17 is rotated rapidly in the clockwise direction as seen in Figure 1, and material is fed into the aerator housing at the inlet end 12. The tapered leading edges 37 of the aerator bars impart to the material glancing blows propelling the material sideways from the direction of rotation, so that a cross fire of particles is set up. Thus, a maximum amount of collision is created between material stmck by adjacent bars, which breaks up the material cakes without destroying the coating on the granular particles. It has been found that the processing time for an aerator of a given size is speeded up from two to four times over conventional designs by the utilization of this cross fire type of aeration, that the service life of the rotating assembly is at 4 least doubled, while the horsepower consumption is from 30% to less. Further, the new combing bars are self-cleaning, and their action greatly reduces or eliminates material build-up within the housing of the aerator.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

1 claim as my invention:

1. In an apparatus for aerating granular material, a housing having a feed inlet and a feed outlet, a rotatable aerator assembly including a shaft rotatably mounted in said housing, said shaft having a portion of polygonal cross-section and a reduced cross-section portion, and a plurality of bars for mounting along said shaft having socket portions with polygonal sockets therein for receiving said polygonal shaft portion to mount said bars in fixed angular relation on said shaft, said socket portions each having a gap therein extending from the outer periphery thereof to the socket thereof and of width to receive said shaft reduced portion, and said socket portions having projections adjacent the respective gaps and overlying the span of the sockets inwardly of the gaps for locking the socket portions of the bars on the polygonal portion of said shaft, whereby said bars may be individually engaged with said shaft at said reduced portion by means of said gaps and thence moved axially of the shaft onto the shaft polygonal portion without disassembling the shaft from the housing and whereby the pr jections on the socket portions serve to retain the bars against radial displacement relative to the shaft polygonal portion.

2. In an apparatus for aerating granular material, a housing having a rotatable aerator assembly therein including a shaft rotatably mounted in said housing, said shaft having a portion of polygonal cross-section and a reduced cross-section portion, and a plurality of combing bars having polygonal sockets receiving said shaft polygonal portion, said combing bars each having a wedge shaped leading edge defined by a pair of oppositely sloping faces, said housing having a feed inlet above said aerator assembly and disposed for delivering material to the combing bars during upward travel thereof, and each of the bars having a gap extending from the outer periphery thereof to said socket of width to fit onto said shaft at the reduced portion thereof but not at the polygonal portion thereof, whereby said bars may be individually engaged with said shaft at said reduced portion and thence moved axially along said shaft onto the shaft polygonal portion without disassembling the shaft from the housing, the shaft polygonal portion being larger than the gaps to retain the combing bars thereon.

References Cited in the file of this patent UNITED STATES PATENTS 180,626 Outcalt Aug. 1, 1876 754,008 Parson Mar. 8, 1904 1,289,542 Rapp Dec. 31, 1918 1,387,725 Johnson Aug. 16, 1921 1,975,406 Reschke Oct. 2, 1934 2,233,727 Bell Mar. 4, 1941 2,551,049 Pinkers May 1, 1951 

